# Hydraulic Radius of a Pipe

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Hydraulic radius, abbreviated as $$r_h$$, is the area cross-section of water in a pipe or channel divided by the wetting perimeter.

## Hydraulic Radius of a Pipe formula

 $$\large{ r_h = \frac { A_c } { P } }$$

### Where:

$$\large{ r_h }$$ = hydraulic radius

$$\large{ A_c }$$ = area cross-section of flow

$$\large{ P }$$ = wetted perimeter